cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A346253 a(n) = A342002(A328623(n)).

Original entry on oeis.org

0, 1, 2, 7, 1, 5, 3, 11, 19, 53, 14, 43, 1, 7, 13, 41, 8, 31, 4, 13, 22, 59, 17, 49, 2, 9, 16, 47, 11, 37, 4, 15, 26, 73, 19, 59, 41, 117, 193, 491, 158, 421, 27, 89, 151, 407, 116, 337, 48, 131, 214, 533, 179, 463, 34, 103, 172, 449, 137, 379, 1, 9, 17, 55, 10, 41, 26, 87, 148, 401, 113, 331, 12, 59, 106, 317, 71, 247, 33, 101, 169
Offset: 0

Views

Author

Antti Karttunen, Jul 11 2021

Keywords

Crossrefs

Programs

  • PARI
    A342002(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= p^(e>0); s += (e/p); n = n\p; p = nextprime(1+p)); (s*m); };
    A346253(n) = A342002(A328623(n)); \\ Rest of program in A328623.
    
  • PARI
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A003557(n) = (n/factorback(factorint(n)[, 1]));
    A342001(n) = (A003415(n) / A003557(n));
    A346233(n) = { my(p=2, m=1); while(n>0, my(d=n%p); if(d>0, m *= p^if(2==p,d,lift(Mod(d, p)/2))); n \= p; p = nextprime(1+p)); return(m); };
    A346253(n) = A342001(A346233(n));

Formula

a(n) = A342001(A346233(n)) = A342002(A328623(n)).